The term computer-aided detection (CAD) is commonly used to refer to the use of computers to analyze medical images to detect anatomical abnormalities therein, and/or the use of computers to otherwise process image information in a manner that facilitates perception of the medical image information by a radiologist. Sometimes used interchangeably with the term computer-aided detection are the terms computer-aided diagnosis, computer-assisted diagnosis, or computer-assisted detection. In an abnormality detection context, a CAD algorithm usually identifies a preliminary set of candidate detections in a medical image and then selects which ones, if any, will qualify as actual CAD detections based on a variety of computed features associated with the candidate detections. The CAD results, i.e., the body of information associated with the operation of the CAD algorithm on the medical image, are most often communicated in the form of annotation maps comprising graphical annotations (CAD markers) overlaid on a diagnostic-quality or reduced-resolution version of the medical image, one CAD marker for each CAD detection. Substantial effort and attention has been directed to improving the performance capabilities of CAD systems.
One issue arising in CAD systems relates to their false positive rate, i.e., the percentage of CAD markers displayed to the radiologist that do not actually correspond to truly suspicious or diseased locations. One proposed method for false positive reduction is proposed U.S. Pat. No. 6,067,372 (Gur, et. al.), which is incorporated by reference herein, but is believed to bring about one or more disadvantages and/or to contain one or more shortcomings that are overcome by one or more of the techniques described hereinbelow. Other issues arise as would be apparent to one skilled in the art upon reading the present disclosure.